Ultrasonic sensing systems provide an efficient and effective method of detecting objects, such as may be utilized in automated industrial manufacturing processes. These sensors require the use of a transducer to produce ultrasonic signals. For example, a transducer for such sensors typically generates an ultrasonic signal that is transmitted in the direction of an object, and a return or reflected signal is received by the transducer. A processor connected to the transducer processes the received signal and determines the presence and/or distance to an object based on the elapsed time between the transmitted and received signals.
Prior art piezoceramic ultrasonic transducers, such as those for use in air-based time-of-flight applications, have generally been designed to have very good long range detection capabilities. In designing these sensors, it has typically been considered desirable to maximize the Q value, i.e., the resonance, of the transducer and minimize the frequency of operation. A high Q value results in greater amplification of a returning signal, and low frequency serves to reduce the attenuation of ultrasound in air because attenuation is a function of frequency. Such prior art transducers have typically been configured as thin disks formed of ceramic material, which traditionally exhibit the benefit of a high Q value.
For various reasons, there are limitations on improving the efficiency and reducing the cost of manufacturing circular shaped ceramic disks, which in turn limits available cost reductions for components incorporating the ceramic disks, such as transducers incorporated into sensors. Accordingly, it is desirable to provide an alternative configuration for a sensor transducer that may incorporate a resonator component having a form factor or shape conducive to efficient production of both the resonator component and the assembled transducer.